Multiple choice

The average weight of 30 students in a class is 60 kg. When 20 new students are admitted, the average weight is reduced by 2 kg. Find the average weight of the new students.

  1. 45 kg

  2. 50 kg

  3. 60 kg

  4. 55 kg
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D Correct answer
Explanation

Total weight of 30 students = 30 * 60 = 1800 kg. Total weight of 50 students = 50 * 58 = 2900 kg. The difference, 2900 - 1800 = 1100 kg, is the weight of the 20 new students. Average = 1100 / 20 = 55 kg.

AI explanation

The total weight of the initial 30 students is 30 multiplied by 60, which equals 1800 kilograms. After admitting 20 new students, the total number of students becomes 50, and the new total weight is 50 multiplied by 58, which equals 2900 kilograms. The total weight of the 20 new students is 2900 minus 1800, giving 1100 kilograms. The average weight of the new students is 1100 divided by 20. The result is 55 kilograms.

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